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Give your ash trees a fighting chance: Treat NOW for ash borer

By the U of A System Division of Agriculture
March 24, 2017

Fast Facts:

  • Now is a good time to treat ash trees for Emerald Ash Borer
  • Proper identification of tree, pest a key first step
  • Cost of removing tree could be higher than cost to treat
  • Professional help may be needed to treat affected trees 

(800 words)

(Newsrooms: with file art

LITTLE ROCK – If you want your ash trees to stand a fighting chance against the emerald ash borer, now through mid-April is the time to treat your trees this invasive pest, say insect and tree experts for the University of Arkansas System Division of Agriculture.  

9000019-SMPT emerald

“Homeowners living in emerald ash borer areas face a tough choice: Either treat their ash trees with an insecticide or let the trees die and pay for proper removal,” said Tamara Walkingstick, associate director of the Arkansas Forest Resources Center, said. “Homeowners should understand that the cost of removing their trees can be much higher than the cost of treating their trees.” 

The emerald ash borer, or EAB, is an invasive beetle from Asia that has now been confirmed in 12 counties in Arkansas. It was first discovered in southwestern Arkansas in 2014 and was confirmed in Randolph County last year. The beetle was first found in the United States in 2002 in Michigan. 

Before treating their trees, homeowners need to take a few steps:

  • Properly identify the tree as an ash tree. EAB in Arkansas has only been found in ash trees. If it’s not an ash, then it’s not EAB damage. There are other native insects that can attack ash trees. 
  • Determine, to the extent possible, the overall condition of the tree. If the tree’s crown was thin last fall, then it might be too late to treat for EAB. This will be impossible to determine until the leaves appear however.
  • The next step is to determine which treatment option might work best. 

“There are several insecticide options available for those people who want to treat their trees. It is important to understand that controlling wood-boring insects with insecticides has always been a difficult proposition. This is especially true with EAB,” Walkingstick said, adding that treatment works best on healthy ash trees or ash trees with less than 30 percent crown damage. 

Unless emerald ash borers have been detected on the property or within 15 to 20 miles of the property, it is not necessary to treat. 

Professional help may be required

John Hopkins, extension urban entomologist for the Division of Agriculture, and Walkingstick said that many of the more effective treatment options might require homeowners to hire professionals to treat their trees. Tree care professionals and arborists whom are certified pesticide applicators have access to more potent chemicals. Many of these chemicals must be injected into the trunk or the soil. 

“Certain systemic bark sprays are also restricted-use pesticides and can only be applied by someone certified by the state,” he said. “Check with your local Cooperative Extension Office for details about these pesticides.” 

“The advantage of tree injections is that the treatment can last for two or three years,” Hopkins said. “The disadvantage is that homeowners cannot use these application methods themselves. 

Homeowners should ask the tree care professional about their familiarity with and ability to use these treatments.” 

Imidacloprid and dinotefuran are systemic insecticides that can be applied as soil drenches or soil injections. Both are sold under numerous brand names for use by professional applicators and homeowners. They can be applied to soil as a drench by mixing the product with water, then pouring the solution directly on the soil around the base of the trunk, or injected a few inches below ground at multiple locations near the base of the tree. The insecticide is taken up by the roots of the tree and then moves, or translocates, throughout the tree. Products designed for homeowners have some restrictions that do not apply to professional formulations. Homeowner products can be applied as a soil drench or as granules that are watered into the soil, but not as a soil injection. Homeowners are also restricted to making only one application per year. 

If homeowners want to use these products, right now is a good time to do so. 

The national clearing house for emerald ash borer information: has the latest, research based information regarding insecticide options for protecting ash trees from EAB. 

Follow the label

Before purchasing or using any pesticide, always read and carefully follow the label directions. 

“Do not apply more with the idea that if a little will work, a lot should work better,” Hopkins said.

Know the signs

For property owners who live in infested counties, or even live adjacent to an infested county or Louisiana parish, it’s a good idea to know the symptoms.

Signs of infestation include: heavy woodpecker feeding, thinning tree crown, D-shaped exit holes, and S-shaped feeding galleries beneath the bark.

Residents also need to remember that a quarantine on the movement of all hardwood firewood to areas outside of the quarantine remains in effect. Thirty-three counties are now included in the quarantine. 

More information can be found at or  A fact sheet about the borer may be found at: “Emerald Ash Borer: A pest of ash trees in Arkansas,” downloadable at

Product mentions in this news story do not imply endorsement by the University of Arkansas System Division of Agriculture.


The Arkansas Cooperative Extension Service offers its programs to all eligible persons regardless of race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer. 

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Media Contact: Mary Hightower
Dir. of Communication Services
U of A Division of Agriculture
Cooperative Extension Service
(501) 671-2126

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